Polygeneration (Power, Water, Hydrogen and Heat) by a Novel Cycle Based on Solid Oxide Fuel Cell Integrated with Micro-Gas Turbine, Metal Hydride, and Desalination

Abstract

In the present research, a novel cycle for simultaneous, distributed, micro-scale production of electricity, water, and hydrogen is proposed based on solid oxide fuel cell (SOFC), micro-gas turbine (MGT), thermal vapor compression single-effect desalination (TVC-SED), and metal hydride (MH). The exhaust of the SOFC is first used in an external steam reformer; then, it turns an MGT and finally produces steam for a TVC-SED unit. Excess hydrogen is stored in a metal hydride. The cycle is modeled thermodynamically and then coded in the Engineering Equation Solver. The models of the SOFC and TVC-SED are validated. The parametric analyses show that the TVC-SED performance is most sensitive to the boiling temperature and compression ratio of ejector and least sensitive to the seawater salinity, motive steam pressure and seawater temperature. The SOFC and the MGT are most sensitive to the reformer temperature. The cycle is applied to a case study in the warm climate in Iran and revealed that the cycle produces the electricity demand of a five-family residential building and water demand of 32 people. The performance ratio of TVC-SED, electrical and overall efficiencies is 1.55, 65.01 and 72.99%. The cycle stores 623.7 kg of hydrogen and sells 1.32 MW of electricity annually.